Control apparatus and method for an internal combustion engine

Abstract

The present invention has a structure of a lean-burn combustion engine 25 for burning a fuel by increasing the proportion of air to the fuel, a swirl control valve 8 for regulating a swirl intensity of combustion air inside an intake port in a lean-burn operation range of the lean-burn combustion engine 25, an accelerator pedal 1 for setting an acceleration request of a driver, and mechanical connection for mechanically connecting the accelerator pedal 1 to the swirl control valve 8, having a mechanism capable of setting the swirl control valve opening so that a lean limit can be expanded. Also, the invention has a structure of an intake system including the swirl control valve for regulating a swirl intensity of combustion air inside an intake port and a a driving mechanism for the valve can be produced easily and at a low cost, and a lean limit can be expanded.

What is claimed is: 
     
       1. A control apparatus for an internal combustion engine for controlling an output torque of said engine of a vehicle having an accelerator pedal for setting an acceleration request for the vehicle and said engine which is a lean-burn engine, comprising: a swirl control valve for controlling a swirl intensity of an air into at least one intake port   of said engine in a lean-burn condition; and a mechanical connection means for connecting said swirl control valve and said accelerator pedal wherein said mechanical connection means includes a delay mechanism keeping all opening of said swirl control valve in said lean-burn condition and an accelerator wire operating said delay mechanism by an operation of said accelerator pedal.   
     
     
       2. A control apparatus for an internal combustion engine according to claim 1, wherein said delay mechanism comprises a first lever on said accelerator pedal side and a second lever on said swirl control valve side. 
     
     
       3. A control apparatus for an internal combustion engine according to claim 2, further including a first return spring provided to said first lever and a second return spring provided to said second lever. 
     
     
       4. A control apparatus for an internal combustion engine according to claim 3, wherein said second return spring has a characteristic such that it extends in a linear direction and its reaction gradually decreases after it increases. 
     
     
       5. A control apparatus for an internal combustion engine according to claim 1, wherein said delay mechanism is provided with a two-stage delay mechanism. 
     
     
       6. A control apparatus for an internal combustion engine according to claim 5, wherein said two-stage delay mechanism is an actuator which is electrically controllable. 
     
     
       7. A control apparatus for an internal combustion engine for controlling an output torque of said engine of a vehicle having an accelerator pedal for setting an acceleration request for the vehicle and said engine which is a lean-burn engine, comprising: a swirl control valve for controlling a swirl intensity of an air into at least one intake port   of said engine in a lean-burn condition; anal a mechanical connection means for connecting said swirl control valve said accelerator pedal wherein said mechanical connection means includes correction means for correcting different individual characteristics and ever-changing characteristics of elements of said vehicle.   
     
     
       8. A control apparatus for an internal combustion engine according to claim 7, wherein said correction means is composed of at least an adjustment screw or a tensioner, or their combination. 
     
     
       9. A control apparatus for an internal combustion engine according to claim 7, wherein said correction means compares an actual opening data output from an opening sensor detecting an actual opening of said swirl control valve with a calculated opening data of said swirl control valve calculated by a method using a lean-burn operation range and changes said calculated opening data to said actual opening data when both data are different. 
     
     
       10. A control method for an internal combustion engine for controlling an output torque of said engine of a vehicle having an accelerator pedal for setting an acceleration request for the vehicle and said engine which is a lean-burn engine, comprising the steps of: controlling a swirl intensity of an air into at least one intake port of said engine in a lean-burn condition using a swirl control valve which is connected to said accelerator pedal by a mechanical connection means; and a step of keeping an opening of said swirl control valve in said lean-burn condition using a delay mechanism which is included in said mechanical connection means and operated by the operation of said accelerator pedal. 
     
     
       11. A control method for an internal combustion engine according to claim 10, wherein said step of keeping an opening of said swirl control valve in said lean-burn condition further comprises a step of using a delay mechanism having a first lever on said accelerator pedal side and a second lever on said swirl control valve side. 
     
     
       12. A control method for an internal combustion engine according to claim 11, wherein said step of using a delay mechanism further comprises using a delay mechanism having a first return spring provided to said first lever and a second return spring provided to said second lever. 
     
     
       13. A control method for an internal combustion engine according to claim 12, wherein said step of using a delay mechanism further comprises using a second return spring which extends in a linear direction, and its reaction gradually decreases after it increases. 
     
     
       14. A control method for an internal combustion engine according to claim 10, wherein said step of keeping an opening of said swirl control valve in said lean-burn condition further comprises a step of using a delay mechanism which is provided with a two-stage delay mechanism. 
     
     
       15. A control method for an internal combustion engine according to claim 14, wherein said step of using a delay mechanism further comprises the step of using a two-stage delay mechanism comprising an actuator which is electrically controllable. 
     
     
       16. A control method for an internal combustion engine for controlling an output torque of said engine of a vehicle having an accelerator pedal for setting an acceleration request for the vehicle and said engine which is a lean-burn engine, comprising the steps of: controlling a swirl intensity of an air into at least one intake port of said engine in a lean-burn condition using a swirl control valve which is connected to said accelerator pedal by a mechanical connection means; and a step of correcting different individual characteristics and ever-changing characteristics of elements of said vehicle by using correction means provided with said mechanical connection means. 
     
     
       17. A control method for an internal combustion engine according to claim 16, wherein said step of correcting further comprises the step of using a correction means comprising at least an adjustment screw or a tensioner, or their combination. 
     
     
       18. A control method for an internal combustion engine according to claim 16, further comprising the steps of: detecting an actual opening data of said swirl control valve;   calculating a calculated opening data of said swirl control valve required to place the engine in a lean-burn condition;   comparing said actual opening data with said calculated opening data; and   changing said calculated opening data to said actual opening data when both data are different.